Dual thermal ablation device and method of use

ABSTRACT

The invention is a multi-functional ablation device that encompasses the use of both heat energy and cryogenic energy as integrated into one medical device. In one embodiment, the medical device integrates a heat source such as RF or HIFU in combination with a source of cryogenic energy such that the multi-functional ablation device is a dual thermal ablation device capable of utilizing either energy source alone or in combination.

RELATED APPLICATIONS

The present application is a Divisional of U.S. patent application Ser.No. 13/761,673 filed Feb. 7, 2013, which claims priority to U.S.Provisional Patent Application Ser. No. 61/595,823 filed on Feb. 7,2012, each of which is incorporated herein by reference in theirentirety.

FIELD OF THE INVENTION

The present invention relates generally to the medical technology fieldand, in particular, to a medical device and method for use in thermaltreatments.

BACKGROUND OF THE INVENTION

Tissue ablation can be performed to remove undesired tissue such ascancer cells or may also involve the modification of the tissue withoutremoval, such as to stop electrical propagation through the tissue inpatients with a cardiac arrhythmia. Often the ablation is performed bypassing energy, such as electrical energy, through one or moreelectrodes causing the tissue in contact with the electrodes to be heatablated. Other devices have employed cryoprobes/catheters to freeze thetissue, other probes/catheters employing the use of such energy sourcesas microwaves and lasers, and high intensity ultrasonic devicesmechanically causing a physical abrasion or destruction of the tissue.

The use of heat energy and cryogenic energy in combination has limitedpractice to date due to several factors including, but not limited to,the relatively new mainstream acceptance and utilization of ablation asa treatment option, as well as the inefficacy in utilizing each sourceof energy independently. Typically, two distinct thermal probes, one todeliver heat energy and one to deliver cryogenic energy are utilized,each technology having a distinct surgical skill set and approach.

Heat energy is routinely used for treating a myriad of diseases. Onemode of heat treatment is radio frequency ablation (RFA). Radiofrequency ablation has been used to treat a variety of cancers andcardiac anomalies. For instance, RFA has been effective in treatingcolorectal liver metastases. This procedure has also been used to treatsaphenous vein varicoses. Other studies have shown that RFA can serve asa minimally invasive method for treating liver tumors even though it isrecognized that the procedure is difficult to monitor in vivo and theblood vessels serve as a heat sink that makes it difficult to controlthe target temperature. Another problem using RFA in treating renaltumors is the necessity of repeat ablation to make the process moreeffective. Radiofrequency ablation has also been used to treat Barrett'sesophagus and atrial fibrillation. When used to treat atrialfibrillation, RFA creates a risk of injury to the adjacent tissues suchas the esophagus. Therefore, esophageal endoscopy is used to screenpatients at risk of esophageal thermal injury after RFA.

Microwave energy has been employed with ablation catheters to try toprovide sufficiently deep lesions. Since the penetration of microwavesinto tissue has a steep exponential decline, the catheter is broughtinto close contact with the tissue. Fat, however, continues to be asignificant barrier.

High powered lasers have also been applied as an ablative energy source,though have a risk of crater formation at the application. Low energylasers produce lesions with a depth related to duration of application.

High intensity focal ultrasound (HIFU) has also been utilized since itis capable of penetrating fat and inducing fast lesions at specificdepths when focused. Tissue is emulsified with millisecond boilingproduced by shock wave heating. This procedure has been used to treatsuch disease states as cardiac arrhythmias and tumors, among others. Theheated zone, however, has intact cells remaining after treatment. Thetreatment using HIFU also has higher complication rates than RFA whentreating atrial fibrillation, halting its use in many countries.

Contrary to heat ablation, cryoablation has been utilized to freeze atarget tissue. The cryogenic energy is used for treating similardiseases as targeted with heat energy. Cryoablation is used to treat ahost of disease states including, but not limited to, liver tumors,actinic keratoses, breast cancer, colorectal cancer, cervicalintraepithelial neoplasia, prostate cancer and atrial fibrillation. Thecryogenic energy (i.e. severe cold) has the advantages of avoiding clotformation and being a natural analgesic. Although cryoablation hasproven to be a successful ablation therapy, complications with theprocedure exist and issues with disease recurrence remain. For example,while trying to reach a designated temperature within a target tissue,the application of freezing temperatures is extended causing overfreezein surrounding non-targeted tissue. In an argon based system, that meansa large portion of the damaged tissue is outside the targeted region. Ina liquid nitrogen based system, colder isotherms are achieved throughoutthe iceball to increase cell death and control destruction of thetargeted tissue, but overfreeze may also damage surrounding non-targetedtissue.

Given that both RFA and cryoablation are commonly used for similarprocedures, the two modalities have each been evaluated for theirrespective advantages and disadvantages. For instance, cryoablationcreates an iceball that can be easily visualized and has a defined zone;whereas RFA is difficult to visualize and can create variabletemperatures especially when adjacent to a heat sink such as bloodvessels. Both procedures, however, can result in survival of residualcells that may result in disease recurrence at a later point in time.

Currently, two separate, independently operated medical devices eachdeliver a single therapy, each having their own technical challenges andapplications. Such challenges include use in a dynamic environment suchas the operating room, high costs, and lengthy procedural times.Individually, present techniques are inefficient, costly, and lack aconcerted effort with technologies that could have collective benefits.

A need exists for a multifunctional catheter and/or probe that utilizesthe benefits of current ablative technologies but limits the undesirableeffects that each individual procedure creates. The integral device willallow for heat ablation and cryoablation within a single unit for dualablation procedures. The ablation device and method of use will be lesstime consuming and more effective than techniques individually utilizedto date. The device will facilitate ease of use while providing costefficient solutions to patient care.

SUMMARY OF THE INVENTION

The present invention applies heat energy and cryogenic energy to atissue using an integral device. The dual ablation device incorporatessources of heat energy and cryogenic energy into one device to allow forthe delivery of heat energy and cryogenic energy to a target tissuesite. This enables controlled, real-time application of a dual thermalablation strategy. The dual thermal ablation system disclosed hereinprovides for a device and a method of use that is capable of deliveringa multitude of therapeutic treatment options, including heat and cold,along with the use of anti-cancer agents, alone or in any combination asdesired.

In one embodiment, a multi-functional ablation device comprises a hybridthermal-cooling system comprising an electrical power supply and acryogen source; a longitudinal body having a proximal end and a distalend wherein the proximal end includes an outer sheath having anelectrical connection contained therein and connected to the electricalpower supply, and wherein the distal end is a closed tip with athermally conductive surface; an ablation zone positioned within thedistal end and defined by the thermally conductive surface; a cryogensupply line disposed through the longitudinal body and interconnectedwith the cryogen source for generating subzero temperatures; a wallhaving an inner surface and an outer surface such that the inner surfacecreates a cryogen return lumen surrounding said cryogen supply line andthe outer surface creates an insulative lumen between the wall and theouter sheath, the wall extended circumferentially through thelongitudinal body; and one or more heating elements disposed within theablation zone of the distal end and contacting the thermally conductivesurface of the closed tip, the heating elements interconnected with theelectrical connection of the longitudinal body for generatinghyperthermic temperatures; wherein the ablation zone transfers subzerotemperatures and hyperthermic temperatures to the thermally conductivesurface.

In one embodiment, the ablation zone is an integral unit configured foralternating use of the subzero temperatures and the hyperthermictemperatures. The electrical power supply comprises thermoelectricelements or resistive heating elements, alone or in combination. Whenthe longitudinal body is a handheld device and configured to attach tothe cryogen source or to the electrical power supply, an umbilicalprovides the interconnection. In one aspect, any length of umbilical maybe utilized. When the longitudinal body is a portable unit, the cryogensource is a cartridge positioned within the longitudinal body. In theportable unit, the electrical power supply is also incorporated in thelongitudinal body.

In the multi-functional ablation device of the invention, the insulativelumen is a vacuum. The insulative lumen may also comprise fibermaterials including fiberglass, rock wool, slag wool, cellulose, naturalfibers, rigid foam, or sleek foils.

One embodiment of the multi-functional ablation device utilizes acryogen source that is a gas cryogen. One embodiment of themulti-functional ablation device utilizes a liquid cryogen. Anotherembodiment of the device utilizes a cryogen source that is a cryogen,liquid or gas, at or above a critical point pressure and cooled to acryogenic temperature below a critical point temperature. In oneembodiment, the cryogenic temperature is more than 10% below thecritical point temperature. In another embodiment, the cryogenictemperature is more than 10% above the critical point pressure, alone orin combination with the cryogenic temperature being more than 10% belowthe critical point temperature.

Embodiments of the invention utilize hyperthermic temperatures in therange of between about +40° C. to about +80° C. or greater; and subzerotemperatures in the range of between about −40° C. to −200° C. orcolder. One embodiment utilizes subzero temperatures in the range ofbetween about −80° C. to −140° C. or colder, and another utilizessubzero temperatures in the range of between about −160° C. to −196° C.This narrower range may incorporate the use of compressed liquidnitrogen, near critical nitrogen, supercritical nitrogen, or similarstates of other cryogens without limitation.

The electrical connections in the device comprise electrical supplywiring for interconnecting with the electrical power supply. Oneembodiment uses an outer sheath to encapsulate the cryogen source andthe electrical power supply. In one embodiment, the longitudinal body isa probe or a catheter.

The hybrid thermal-cooling system of the invention comprises anelectrical power supply having at least one of radiofrequency energy,microwave energy, ultrasound energy, laser light energy, orthermoelectric energy; and a cryogen source comprising a thermoelectricmodule or a cryogenic fluid, wherein the cryogenic fluid is in apressurized state, compressed liquid state, critical state, nearcritical state, or supercritical state. The cryogenic fluid may beutilized at a temperature above a critical point temperature also.

A method for performing tissue ablation is disclosed in embodiments ofthe present invention comprising: a longitudinal body having a proximalend and a distal end wherein the proximal end includes an outer sheathhaving electrical connections contained therein and wherein the distalend is a closed tip with a thermally conductive surface, the thermallyconductive surface defining an ablation zone; providing a hybridthermal-cooling system comprising an electrical power supply and acooling source configured for integration with the longitudinal body atthe proximal end; designating a tissue site for ablation; positioningthe ablation zone of the multi-ablation device at a first position ofthe tissue site; producing heat energy from the electrical power supply;producing cooling energy from the cooling source; directing the heatenergy or the cooling energy through the longitudinal body to theablation zone for a first time period to damage the tissue site;directing the heat energy or the cooling energy through the longitudinalbody to the ablation zone for a second time period to damage the tissuesite; and removing the ablation zone of the longitudinal body from thetissue site; wherein the steps of directing the heat energy or thecooling energy for the first time period and the second time perioddestroy the tissue site alone or in combination.

In one embodiment, the method further comprises a step of repeating thesteps of directing the heat energy or the cooling energy for the firsttime period and the second time period, alone or in combination. Themethod may further comprise a step of repositioning the ablation zone ofthe longitudinal body to a second position in the tissue site.

When thermoelectric modules are utilized, the heat energy is formedthrough a thermoelectric process. When an electric power supply isconnected to resistance wires or heater unit by way of electrical supplywiring, the heat energy is formed through a resistive heating process.Electrical wiring extending through the longitudinal body interconnectsthe energy source with the heating or cooling unit in the ablation zoneof the tip.

Cooling energy may be created by a cryogen source including argon,nitrous oxide, carbon dioxide, helium, hydrogen, nitrogen, oxygen,methane, chlorofluorocarbons, hydrochlorofluorocarbons, alcohols, or anycombination thereof. Cooling energy may also be created bythermoelectric cooling in a thermoelectric module using a semiconductorpellet soldered to an electrically-conductive material. In oneembodiment, during the steps of directing the heat energy or the coolingenergy for the first time period and the second time period, athermoelectric module directs electrical current through at least twodissimilar conductors such that a first flow of current in one directionabsorbs heat and a second flow of current in an opposite directionreleases heat.

Other embodiments include utilizing the multi-functional ablation devicein combination with anti-cancer agents, either simultaneously or as anindependent step. During the method of utilizing the multi-functionalablation device, the steps of directing heat energy or cooling energyfor the first and second time periods can activate cell pathways toinduce apoptosis. Aspects of the invention include performing the stepsof directing the heat energy or the cooling energy for the first timeperiod and the second time period sequentially. Where zones of ablationare isolated at the thermally conductive surface, the steps of directingheat energy or the cooling energy for the first time period and thesecond time period can be performed simultaneously.

An embodiment of the present invention is also a tissue ablation probecomprising: a longitudinal body having a proximal end and a distal endwherein the proximal end includes an outer sheath having electricalconnections contained therein and wherein the distal end is a closed tipwith a thermally conductive surface, the thermally conductive surfacedefining an ablation zone; a hybrid thermal-cooling system comprising anelectrical power supply connected to the electrical connections of thelongitudinal body, and a cooling line positioned within the longitudinalbody and interconnected with a cooling source at the proximal end; and acontroller, or on/off switch, for selectively distributing heat ablationenergy and cryogenic cooling energy; wherein the ablation zone is anintegral unitary treatment zone such that the thermally conductivesurface absorbs and releases heat to destroy a tissue site. The tissueablation probe is interconnected at a console where an electric sourceand cryogen source are present. The tissue ablation probe is also anindependent handheld device detachable from the console or anindependent unitary ablation device.

Various embodiments of the tissue ablation probe include tips in anynumber of configurations, any size and material composition. One tip isa needle. Another tip is a wedge. Another tip is a paddle.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate various embodiments of thepresent invention, and, together with the description, serve to explainthe principles of the invention. The various features are notnecessarily drawn to scale. In fact, the dimensions may be arbitrarilyincreased or decreased for clarity of discussion. In the drawings:

FIG. 1 is an internal side view of an illustrative embodiment of thehandheld device in FIG. 4 of the invention.

FIG. 2 is an internal depiction of an illustrative embodiment of adevice of the invention.

FIG. 3 is an internal side view of an illustrative embodiment of adevice of the invention.

FIG. 4 is an external design of an embodiment of the invention.

FIGS. 4A, 4B, and 4C depict tip configurations of the invention.

FIG. 5 is an internal view of an embodiment of the handheld invention.

FIG. 6 is an embodiment of the invention interconnected with a consolethat houses a power supply and a cryogen source.

DETAILED DESCRIPTION

Reference will now be made in detail to the present embodiments of theinvention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers will be usedthroughout the drawings to refer to the same or like parts.

Combination approaches to treat various disease states, includingcancer, have moved to the forefront of research and clinical practice.In most cases, combination approaches involve the use of multiple drugssuch as anti-cancer agents. Other cases might involve the use ofablation strategies, such as heat energy or cryogenic energy, incombination with anti-cancer agents. The use of heat energy incombination with cryogenic energy provides for an effective combinationablation strategy to target unwanted tissue.

The present invention provides a multi-ablation device that is a probeor catheter having the lethal effects of ablative heat energy andablative cryogenic energy. The thermal probes and catheters are utilizedfor performing ablation at a target tissue site in a subject.

In FIG. 4, an external view of a multi-functional ablation device 400 isillustrated. The device 400 has a longitudinal body 402 with anattachment 404 for connection with a handle 406. Embodiments of themulti-functional ablation device 400 can house different internalcomponents within the longitudinal body 402 as well as differentinternal components of the handle depending on internal and externalenergy components. (Various embodiments of the longitudinal body aredepicted in FIG. 1, FIG. 2, and FIG. 3.) The handle 406 has an on/offswitch 410 to operate the electrical power supply and the cryogen supplyunits. (As seen in FIG. 5, a handheld unit contains both energy supplyunits). The on/off switch 410 is a controller for selectivelydistributing heat ablation energy and cryogenic cooling energy asdesired.

At the distal end of the longitudinal body 402 is a closed tip 408.FIGS. 4A, 4B, and 4C depict three different configurations of a closedtip 408, though any tip maybe utilized as modified in a current designor as currently used with balloon catheters and other probe designs.FIG. 4A illustrates a pointed needle tip 409 for puncturing into atissue site. The ablation zone 441 is depicted at the distal end. FIG.4B illustrates a wedge tip 411 for linear ablation such that the wedgetip 411 is placed longitudinally in the tissue to destroy cells along alinear path created by the ablation zone 442. FIG. 4C illustrates apaddle tip 413 creating the ablation zone 443 and having a flat surface445 for surface ablation. Without limitation, various probe tips may beutilized with the present invention as configured for integration withthe longitudinal body or for removable attachment with the longitudinalbody. Further, tips allow for customization of the ablation zone to eachtargeted tissue region.

In the embodiments of the invention, the ablation zone is situatedwithin the distal end and defined by the thermally conductive surface inthat the surface that is utilized to transfer heat and/or cold to thetissue site defines a specific size, shape and dimension. For exemplarypurposes only and not limitation, a needle probe can be used that has anablation zone 1.0 cm in length×1.5 mm diameter as created by thethermally conductive surface that surrounds the heating and freezingcomponents; thus, the ablation zone is the three-dimensional treatmentzone or may be a two-dimensional surface such as a wedge that has onethermally conductive surface defined by a specific length and width. Thethermally conductive surface can therefore be formed in various areas onthe surface of the closed end tip.

The internal components of the longitudinal body 402 of the dualablation device 400 are depicted in FIG. 1. In the embodiment depicted,a hollow longitudinal body 402 has an outer sheath 103 with an open end104 at the proximal end for attachment to an energy source and a closedend tip 106 at the distal end for ablation at the tissue site. At theclosed tip 106 is a thermally conductive surface 111 made of stainlesssteel or other conductive metallic or polymeric material. In theembodiment depicted in FIG. 1, a cryogen gas supply line 108 proceedsthrough the longitudinal body 402 as inserted at the open end 104(proximal to a point of attachment) and terminating within the closedend tip 106 (at a distal end). A thermoelectric heater coil 110 ispositioned within the closed end tip 106. An electrical connection wire112 runs through the length of the longitudinal body 402 to directelectrical current to the heater coil 110. The heater coil 110 mayinclude or be replaced with resistance wire to generate heat. Togetherthe thermoelectric heater coil 110 and cryogen supply line 108 in theclosed end tip 106 form an ablation zone 115, also referred to herein asthe dual ablation zone 115. A return lumen 114 surrounds the supply line108 and circumferentially extends the length of the longitudinal body402, allowing the return of gas from the cryogen supply line 108 in thetip 106 back to its source or to be vented into the atmosphere. Thevacuum lumen 116 is an insulative lumen 116 that serves as an insulatorfor the cryogen supply line and electrical connection wires 112.Insulative lumens may also utilize fiber materials including fiberglass,rock wool, slag wool, cellulose, natural fibers, rigid foam, or sleekfoils. The open end 104 is integrated with the attachment 404 forinterconnection with a handle 406. The open end 104 may also beconfigured for direct attachment with an umbilical.

In this embodiment, the cryogen gas supply line 108 is a Joule-Thomsoncryogen gas supply line 108. In another embodiment the cryogen supplyline 108 is a liquid cryogen. Embodiments also integrate various statesof cryogen in the supply line 108 such as a cryogen at or above acritical point pressure. In one aspect, the cryogen can then be cooledto a cryogenic temperature below the critical point temperature. Wherecryogenic temperatures and pressures are near critical, or more than 10%below the critical point temperature and more than 10% above thecritical point pressure, or supercritical, the reduced surface tensionof the fluid allows for a reduced friction flow and thereby preventsvapor lock.

In the embodiment of FIG. 1, the multi-functional ablation device has ahybrid thermal-cooling system that operates at hyperthermic temperaturesin the range of between about 40° C. to about 80° C. or greater; and thecooling temperatures operate at subzero temperatures in the range ofabout −40° C. to about −200° C. or colder. In another aspect,temperatures can be utilized between about −80° C. to −140° C. or colderand also in the range of between about −160° C. to about −196° C.

In one aspect, the dual ablation probe 400 is connected to a systemcomprising a CO₂ or N₂ gas cartridge system (e.g. 12 g cylinders) incombination with electrical connection wires interconnected withresistance wire or other heating mechanism within the probe. Any number,size and shape of cartridges may be utilized depending on the size andconfiguration of the handheld device. The configuration illustrated inFIG. 4 delivers effective freezing and/or heating capability tophysically destroy cells and to activate cell pathways that induceapoptosis. The heating and freezing in combination works to ablatetissue (a) physically by cryo-destruction and heat-destruction (e.g.thermal radiation, radio frequency energy, ultraviolet light andionizing radiation); and/or (b) molecularly through apoptotic celldeath. FIG. 4 illustrates a handheld device that has a footprint assmall as possible and easy to manipulate, though any size and shape ofthe device may be implemented. In another aspect, the ablation devicecan be connected to compressed gas systems or energy sources ascurrently used in the medical industry and in patient care.

FIG. 2 illustrates an embodiment of a longitudinal body 202 such thatthe thermoelectric heater coil 110 of longitudinal body 402 (from FIG.4) is replaced with Peltier heater chips 220 in the ablation zone 225 ofthe closed end tip 206. The closed end tip 206 is formed having athermally conductive surface 211 that defines the boundaries of theablation zone 225. The longitudinal body 202 is encompassed by an outersheath 232 that contains the supply line 208, return lumen 214, and aninsulative lumen 216. Electrical connecting wires 222 extend through thelongitudinal body 202 to connect and supply power to the Peltier heaterchips 220. Together the Peltier heater chips 220 and the cryogen supplyline 208 form a dual ablation zone 225. The open end 204 can beintegrated with an attachment to affix to a handle or may be configuredfor connection with an umbilical that interconnects with an externalenergy source.

Another embodiment of a probe of the present invention is illustrated inFIG. 3 as a hollow longitudinal body 302 surrounded by an outer sheath332. The longitudinal body 302 has a closed end tip 306 and an open end304 for attachment to an energy source, hyperthermic, cryogenic orotherwise. A vacuum lumen 316 serves as an insulator between the outersheath 332 and the open space 314 of the longitudinal body 302. In thisembodiment, a series of Peltier heater chips 311 line internal wall 312of the closed end tip 306. Electric wires 322 extend through thelongitudinal body 302 from the open end 304 and connect to the Peltierheater chips 311 at the distal end. The Peltier heater chips 311 in theclosed end tip 306 form the ablation zone 315 such that a dual ablationzone 315 is created when the series of Peltier heater chips 311 functionin heating and/or cooling the closed end tip 306. The series ofminiature Peltier cooling chips are placed and configured within thedevice to deliver effective ablation temperatures between about 40° C.to about 70° C. or higher and freezing temperatures less than about −40°C. In one aspect, a single Peltier chip is utilized to create ahyperthermic temperature of about 70° C., and provides a coldtemperature of about −40° C. when placed in contact with tissue. Heatextraction, however, is not cumulative when multiple chips are utilized.

Calculations of probe performance suggest a string of 4-6 Peltiermicrochips in the probe tip provide an effective wattage of coolingpower to freeze a 1 cm³ volume of tissue to less than about −40° C.Heating of the probe is accomplished via DC current reversal through thePeltier chip, thereby creating heat. As with cooling, DC voltage andvarious chip cascading/bypass configurations are embodied within theinvention to allow for optimal device configuration. Heat calculationssuggest that a bypass circuit be integrated into the system as about twoto four Peltier chips are utilized to deliver temperatures of about +50°C.

The idea to utilize various approaches to treat various disease states,including cancer, has been realized in combining current ablationtreatments. The use of heat energy and cryogenic energy to treat atarget tissue enables controlled, real-time application of a dualthermal ablation strategy. Further, the device is capable of deliveringa multitude of ablation approaches including freezing, heating, andanti-cancer agents alone or in any combination desired.

FIG. 5 further illustrates the internal components of a handheld device500. Here, the device is a portable independently operable unit 500. Anelectrical power source 520 is a battery 520 housed within the handle506 along with a cryogen source cartridge 521. A cryogen supply line 501is attached to the cryogen source cartridge 521 through a connector 503and extends through the longitudinal body 502 to the closed end tip 508.Cryogenic temperatures are transferred to the thermally conductivesurface 555 of the ablation zone 558 at the closed end tip 508. A returnline 559 allows for the venting of any cryogenic fluid to the atmospheredue to pressure generated at the tip. An electrical connection wire 505relays electrical energy to the closed end tip 508 where a heatingelement, e.g. heater coil or Peltier chip (not illustrated), is locatedto generate hyperthermic temperatures at the thermally conductivesurface 555 of the ablation zone 558. An on/off switch 510 controls thedelivery of hot or cold temperatures to the probe tip 508. The handhelddevice 500 may also be configured to interconnect with a console (suchas that in FIG. 6) that houses a separate electrical power supply and/orcryogen supply.

FIG. 6 depicts a multi-functional ablation device 600 of the inventionwith a dual ablation probe 400 detachable from an energy supply console602. An umbilical 604 connects to the dual ablation probe 400 at a tightjunction 606 and also to the console 602 at an easy-attach connection608. This allows the dual ablation probe 400 to be attached to a numberof energy sources. The console 602 houses an electric supply that has atleast one source of hyperthermic energy including radiofrequency energy(RF), microwave energy, high frequency ultrasound energy (HiFU), laserlight energy, or thermoelectric energy, alone or in combination. Theconsole 602 houses a cryogen source that includes at least one of athermoelectric module or a cryogenic fluid such that the cryogenic fluidis in a pressurized state, compressed liquid state, critical state, nearcritical state, or supercritical state. For exemplary purposes only andnot limitation, supercritical nitrogen (SCN) systems, compressed liquidcryogen at its critical state, or pressurized argon systems may beutilized as the cryogen source.

Aspects of the system facilitate the use of multiple umbilicals wherethe sources of heat energy or cooling energy vary. The umbilical 604 isabout 20 feet in length or less. Without limitation, however, theumbilical 604 may be any length up to about 35 feet or more as desiredor practicable.

One embodiment of the invention uses an integral dual thermal ablationprobe which delivers heat energy and cryogenic energy to a targettissue. The device is designed to increase tissue ablation through theco-application of heat and freezing to the target cancer tissue whilereducing collateral damage to surrounding non-targeted tissues. Thisnovel dual thermal ablation device allows for more effective,reproducible, and controllable tissue ablation to treat diseased tissue.

In addition to providing dual heat energy and cryogenic energy ablationmodes within a single medical device, the system also provides for theintegrated delivery and use of anti-cancer agents which workindependently or in combination with either mode of treatment.

Operational use of the dual thermal ablation device allows forapplication of any combination of heating, freezing, or anti-canceragent application to the target tissue. For exemplary purposes, use ofthe device to ablate a target tissue area on the skin comprisesapplication of an anticancer agent to the target tissue, followed byfreezing of the target, heating of the target, and then a final freeze.Other methods of application include, but are not limited to, proceduressuch as: freeze alone; heat alone; freeze/heat/freeze; heat/freeze/heat;agent/heat/freeze; agent freeze/agent/heat; or any combination ofapplication of freezing, heating, and/or any number of anti-canceragents.

The combination of treatment into a single modality supports theutilization of ablation techniques in personalized molecular medicine.The integral device results in more effective cell ablation of thetarget tissue with minimal damage to neighboring healthy tissue. Themulti-functional probe or catheter is a hand-held, bench top or portabledevice that provides a physician easy and rapid access to real-timeindividual and/or combined application of heat energy, cryogenic energy,and/or administration of other medicinal therapy (e.g. anti-canceragents).

One embodiment of the device is utilized for the target ablation ofcardiac tissue. Various other embodiments utilize the device in thetarget ablation of tissues of the skin, esophagus, bladder, endometrium,breast, prostate, liver, heart, pancreas, lung, brain, and kidney. Theinvention delivers both heat energy and cryogenic energy to theapplication tip of a pen-like hand-held device, such as to the tip of aprobe or catheter. Aspects of the invention also integrate a table topor modular unit with the associated probes or catheters.

Mechanisms for delivering the energy sources (i.e. hot or coldtemperatures) include use of any combination of cascaded thermoelectricPeltier cooling and heating system, compressed gas (e.g. CO₂, Ar₂, orN₂) cooling, and/or resistance wire heating. Each approach generatesprobe tip temperatures for ablating undesirable tissue: Tip temperaturesrange between about +40° C. and +80° C. or greater (heat mode) andaround about −40° C. to −80° C. or colder (freeze mode), depending onthe energy source and configuration utilized. For instance, cryogenicenergy produced temperatures less than about −40° C. which effectivelyablates cancerous tissue. In one configuration, the multi-functionalapproach using Peltier cooling generates hyperthermic temperatures atthe target site of about +40° C. to +50° C. and freeze mode temperaturesof about −42° C. For exemplary purposes and not limitation, cryogeniccooling sources generate tip temperatures of about −70° C. to −80° C. orcolder.

In another embodiment, the dual thermal ablation device comprises aconfiguration of a cryoablation system in combination with a thermalablation device such as radiofrequency (RF), high frequency ultrasound,laser, thermal pellets, or any other approach to delivering heating andfreezing in tandem to a target tissue.

As described, several configurations of the device are embodied in theinvention including, but not limited to, CO₂ or resistance wire andthermoelectric (cascaded Peltier) heating and cooling. Severaladvantages of the system include efficiency, cost reduction,miniaturization capabilities, and reliability.

In conjunction with the multi-functional thermal device (heating andcooling mechanism), a series of ablation application tips have beendeveloped. The tip configurations include, but are not limited to, abouta 2.0 mm diameter×2.0 cm long needle, about a 1.5 mm diameter×1.0 cmlong needle, about a 5.0 mm wide×1.0 cm long wedge, and about a 1.0 cmdiameter paddle. These various tips provide for a variety of treatmentapproaches as integral with the heat energy delivery and/or cryogenicenergy delivery.

Though the multi-functional ablation device has been described in termsof its preferred embodiments, the various embodiments and aspects of theinvention may be utilized in various treatment procedures in a patient.The use of a multi-functional device benefits the treatment proceduresof several organs and other tissues of a patient, including inter-tissueand surface ablation, ablation of tumors, and epicardial and endocardialablation.

Other embodiments of the invention will be apparent to those skilled inthe art from consideration of the specification and practice of theinvention disclosed herein. It is intended that the specification andexamples be considered as exemplary only, with a true scope and spiritof the invention being indicated by the following claims. In addition,where this application has listed the steps of a method or procedure ina specific order, it may be possible, or even expedient in certaincircumstances, to change the order in which some steps are performed,and it is intended that the particular steps of the method or procedureclaim set forth here-below not be construed as being order-specificunless such order specificity is expressly stated in the claim.

What is claimed is:
 1. A method for performing tissue ablationcomprising: providing a longitudinal body having a proximal end, adistal end, and one or more heating elements within said distal end,wherein said proximal end includes an outer sheath having electricalconnections contained therein, wherein said distal end is a closed tipwith a thermally conductive surface, said thermally conductive surfacedefining an ablation zone, and wherein said one or more heating elementsline an internal surface of said ablation zone and contact saidthermally conductive surface of said closed tip, said one or moreheating elements being interconnected with said electrical connections;providing a hybrid thermal-cooling system comprising an electrical powersupply and a cooling source configured for integration with saidlongitudinal body at said proximal end; designating a tissue site forablation; positioning said ablation zone of said multi-ablation deviceat a first position of said tissue site; producing heat energy from saidelectrical power supply; producing cooling energy from said coolingsource; directing said heat energy or said cooling energy through saidlongitudinal body to said ablation zone for a first time period todamage said tissue site; directing said heat energy or said coolingenergy through said longitudinal body to said ablation zone for a secondtime period to damage said tissue site; and removing said ablation zoneof said longitudinal body from said tissue site; wherein said steps ofdirecting said heat energy or said cooling energy for said first timeperiod and said second time period destroy said tissue site alone or incombination.
 2. The method of claim 1, further comprising a step ofrepeating said steps of directing said heat energy or said coolingenergy for said first time period and said second time period, alone orin combination.
 3. The method of claim 1, further comprising a step ofrepositioning said ablation zone of said longitudinal body to a secondposition in said tissue site.
 4. The method of claim 1, wherein saidheat energy is formed through a thermoelectric process or through aresistive heating process.
 5. The method of claim 1, wherein saidcooling energy is created by a cryogen source including argon, nitrousoxide, carbon dioxide, helium, hydrogen, nitrogen, oxygen, methane,chlorofluorocarbons, hydrochlorofluorocarbons, alcohols, or anycombination thereof.
 6. The method of claim 1, wherein said coolingenergy is created by a thermoelectric module using a semiconductorpellet soldered to an electrically-conductive material.
 7. The method ofclaim 1, wherein said steps of directing said heat energy or saidcooling energy for said first time period and said second time periodutilize a thermoelectric module which directs electrical current througha Peltier chip such that a first flow of current in one directionabsorbs heat and a second flow of current in an opposite directionreleases heat.
 8. The method of claim 1, wherein said steps of directingheat energy or cooling energy for said first time period and said secondtime period activates cell pathways to induce apoptosis at said tissuesite.
 9. The method of claim 1, wherein said steps of directing saidheat energy or said cooling energy for said first time period and saidsecond time period are performed sequentially or simultaneously.
 10. Atissue ablation probe comprising: a longitudinal body having a proximalend and a distal end, wherein said proximal end includes an outer sheathhaving electrical connections contained therein, wherein said distal endis a closed tip having one or more thermoelectric elementsinterconnected with said electrical connections and a thermallyconductive surface, said thermally conductive surface defining anablation zone, and wherein said one or more thermoelectric elements linean internal surface of said ablation zone; a hybrid thermal-coolingsystem comprising an electrical power supply connected to saidelectrical connections of said longitudinal body, such that saidelectrical connections connect with said one or more thermoelectricelements at said thermally conductive surface; and a controller forselectively distributing heat ablation energy and cryogenic coolingenergy to said ablation zone; wherein said ablation zone is an integralunitary treatment zone such that said thermally conductive surfaceabsorbs and releases heat to destroy a tissue site.
 11. The tissueablation probe of claim 10, further comprising a cooling line positionedwithin said longitudinal body and interconnected with a cooling sourceat said proximal end.
 12. The tissue ablation probe of claim 10, whereinsaid tissue ablation probe is an independently operable handheld device.13. The tissue ablation probe of claim 10, wherein said one or morethermoelectric elements is a heater coil connected to said electricalconnections and positioned in contact with said closed tip, and whereinsaid closed tip transfers heat energy to said thermally conductivesurface.
 14. The tissue ablation probe of claim 10, wherein said one ormore thermoelectric elements are Peltier chips positioned within saidclosed tip and interconnected with said electrical connections of saidlongitudinal body for directing electrical current through the Peltierchips such that a first flow of current in one direction absorbs heatand a second flow of current in an opposite direction releases heat atsaid thermally conductive surface.
 15. A tissue ablation probecomprising: a longitudinal body having a proximal end and a distal end,wherein said proximal end includes an outer sheath having electricalconnections contained therein, wherein said distal end is a closed tiphaving one or more thermoelectric elements interconnected with saidelectrical connections and a thermally conductive surface, saidthermally conductive surface defining an ablation zone, and wherein saidone or more thermoelectric elements line an internal surface of saidablation zone; a hybrid thermal-cooling system comprising a cryogensource and an electrical power supply, said electrical power supplyconnected to said electrical connections of said longitudinal body suchthat said electrical connections connect with said one or morethermoelectric elements at said thermally conductive surface; and acontroller for selectively distributing heat ablation energy andcryogenic cooling energy to said ablation zone.
 16. The tissue ablationprobe of claim 15, wherein said electrical power supply provides atleast one of radiofrequency energy, microwave energy, ultrasound energy,laser light energy, or thermoelectric energy; and said cryogen sourceprovides a thermoelectric module or a cryogenic fluid, wherein saidcryogenic fluid is in a pressurized state, compressed liquid state,critical state, near critical state, or supercritical state.
 17. Thetissue ablation probe of claim 15, further comprising a cooling linethat is positioned within said longitudinal body and interconnected witha cooling source at said proximal end of the longitudinal body.
 18. Thetissue ablation probe of claim 15, wherein said one or morethermoelectric elements is a heater coil connected to said electricalconnections and positioned in contact with said closed tip, and whereinsaid closed tip transfers heat energy to said thermally conductivesurface.
 19. The tissue ablation probe of claim 15, wherein said one ormore thermoelectric elements are Peltier chips positioned within saidclosed tip and interconnected with said electrical connections of saidlongitudinal body for directing electrical current through the Peltierchips such that a first flow of current in one direction absorbs heatand a second flow of current in an opposite direction releases heat atsaid thermally conductive surface.